1. Field of the Invention
The present invention relates to an auto-lock style continuity test unit, and more specifically relates to continuity testing for automobile wire harnesses, testing of sub-assemblies (hereinafter referred to as xe2x80x9cwire assemblyxe2x80x9d) including a wire harness, or testing between electrical devices.
2. Description of the Related Art
The wire assembly is, in general, an electrical wiring system which forms a predetermined circuit in connection with a plurality of wires. Terminal fittings, which include a male or female type connected with each electric wire, are incorporated in a connector housing, and are protected by a so-called lance type non-slip element. By connecting a connector housing which incorporate a male terminal fitting with one which incorporates a female terminal fitting, electrical connection is achieved between both terminal fittings. The terminal fittings mentioned above are not permitted to slip off from the connector housing with the external force normally applied during use or to encounter a nonconductive failure. Thus, continuity test units have conventionally been proposed to test the electrical continuity or mechanical standstill condition of terminal fittings incorporated in the connector housing.
The continuity test units heretofore proposed have been provided with a housing holder which retains a connector housing, and a test device which carries probe pins to contact the terminal fittings in the retained connector housing. In this case, among the above-mentioned probe pins, a so-called 2 probe-form (which has a switch function and is well known in the art) incorporates a spring member having a capacity allowing a comparatively larger load so as to push off a terminal fitting which is incorrectly loaded into the connector housing, and to allow electrical continuity to be achieved as long as this spring member is deflected a certain distance.
The above-mentioned housing holder and test device are mutually constructed so as to be relatively movable, and the probe pins are brought into contact with the terminal fittings by relatively moving the housing holder and check device using a manual lever, such as a toggle lever.
However, moving the housing holder and test device using a manual lever is undesirable due to poor workability and because it is labor intensive. That being the case, currently so-called auto-lock continuity test units, similar to the invention disclosed below, are mainly proposed which allow continuity testing by positioning a connector housing on probe pins by merely inserting the connector housing to be checked. (See, for example, Japanese Patent Publications (Unexamined) HEI 5-288792 and U.S. Pat. No. 5,498,966.)
The structure comprises a connector insertion area for inserting a connector housing to be checked, probe pins mounted inside the connector insertion area, and a connecting tool for connecting the back of the inserted connector, and is arranged to allow the connector to fasten to the connector insertion area by shifting the above-mentioned connecting tool in a direction across the axial direction of the connector at a certain time.
With the above-mentioned prior art, since the probe pins were directly mounted on a connector insertion area, there was a limitation to an adaptable probe pin. That is, provided a 2 probe-form pin as mentioned above was adopted, it was necessary to push the connector housing with the worker""s finger force against the control force of a spring member which is provided for the probe pins in case of mounting the connector housing into the connector insertion area. But, since the force required for deflecting a spring member of the probe pins is normally more than 4 kgf, there was the inconvenience of not to be able to insert the connector housing into a connector insertion area with normal worker""s finger for such work which required a greater burden on workers.
The present invention was made to overcome the above-mentioned inconvenience, and the object is to provide an auto-lock type continuity test unit not limited to a few probe pins.
In order to solve the above-mentioned problems, the present invention is directed to an auto-lock type continuity test unit which is provided with a connector receiving member into which a connector housing, which becomes a test object, can be inserted. A test area is provided which contains probe pins for continuity testing of test terminal fittings of a connector housing inserted into a connector receiving member, and a connecting mechanism is provided to fasten the corresponding connector housing in such a manner capable of testing the continuity against the test area with a connector receiving member being shiftable both to a connected state that connects with the back of the connector housing inserted in the connector receiving member and a released state that permits removal of the connector housing from the connector receiving member.
A driving mechanism is provided to relatively shift a connector receiving member and test area between an engaged state and a separated state by moving a connector receiving member and a test area to an engaged state in which the test area engages in a continuity testing manner and to a separated state away from the connector housing.
A control mechanism is provided to control the driving mechanism so that the connector receiving member and the test area move relatively from a separated state at a predetermined time by shifting the connector receiving member relative to the test area to the engaged state as a result of insertion of the connector housing into the connector receiving member.
With the present invention which contains this particular item, when a worker inserts a connector housing into a connector receiving member, insertion of the connector housing can be made without interference between probe pins of the test area and terminal fittings of the connector housing by relatively shifting a connector receiving member and a test area to a separated state. In addition, based on the insertion of the connector housing, since the control mechanism relatively shifts the connector receiving member and test area, the test area engages the retained connector housing and carries out a predetermined continuity test. Furthermore, after the predetermined timing, for example, when a continuity test comes to an end, the control mechanism again controls the driving mechanism, and then relatively returns the connector receiving member and check area. Therefore, the worker can easily remove the connector housing from the connector receiving member. To provide relative movement between the connector receiving member and the check area, any structure, in which either one is fixed while the other shifted, or both are shifted, may be provided.
In addition, with a preferred embodiment, an interlocking mechanism for interlocking the connecting mechanism with the driving mechanism is provided so that the connector housing is locked in the connector receiving member at least when testing, with the connecting mechanism shifted between a connected state and a released state by interlocking with the relative movement between the connector receiving member and the test area.
With the present invention containing this feature, an opening and closing action of the connecting mechanism is achieved by interlocking the relative movement between the connector receiving member and the test area by a driving mechanism.
In addition, with the preferred embodiment of an interlocking mechanism, a link member is included which links the connecting mechanism to the test area so that inserting the connector housing into a connector receiving member is made by maintaining the connecting mechanism in the released state at an initial condition.
With the present invention containing this feature, since the connecting mechanism is moved to a released state at the initial condition by a link member, it is possible to easily insert the connector housing into the connecting receiving member.
In addition, the preferred embodiment of the interlocking mechanism includes a link member which links a connecting mechanism with a testing device so that the connecting mechanism is maintained in a connected state in an initial condition and also the connecting mechanism is allowed to be pushed into a released state by a connector housing to be inserted into the connector receiving member, and a driving mechanism for interlocking capable of driving the link member independently from the driving mechanism.
With the present invention which contains this particular feature, since the connecting mechanism is maintained in a connected state in an initial condition, a worker inserts a connector housing into a connector receiving member by pushing and widening a connecting mechanism from a connected state to a released state. Therefore, the connecting mechanism cannot shift from a widened state to the connected state unless the connector housing is completely inserted into the connector receiving member.
In addition, the link member in another embodiment is provided in a relatively shiftable manner to the test area, so that the connecting mechanism permits shift to a released state when the test area is in a separated state and also the connecting mechanism controls the shift to a released state when the test area is in an engaged state.
With the present invention which contains this particular feature, relatively shifting the link member to the test area allows the connector housing to be detached by shifting the connecting mechanism to a released state in an initial condition. On the other hand, when the test area is in an engaged state, there may be such a case that a significant force is imparted in an extraction direction from the connector receiving member by probe pins or the like in the connector housing. In this case, the connecting mechanism is controlled to shift to a release state, which protects the connector housing from being inadvertently removed from the connector receiving member.
Another embodiment of the present invention is provided with an elastic body capable of controlling the connector housing in a removal direction which is inserted into the connector receiving member.
The present invention which includes this specific feature can eject the connector housing from the connector receiving member by the elastic body. This elastic body, by being provided in the connector receiving member, is structured in a relatively shiftable manner to the test area. Therefore, the contact force by the elastic body can be set to a sufficient level to exclusively eject the connector housing.
According to a first aspect of the present invention, when a connector housing is inserted into a connector receiving member by a worker, insertion of the connector housing is made possible without interference between the probe pins in the test area and the terminal fittings of the connector housing, thus making it possible for the connector housing to be inserted into the connector receiving member without regard to the type of probe pins. Therefore, according to the present invention, either 1 probe-form (which does not have a switch function and which is also well known in the art) style or 2 probe-form style can be easily adopted, thereby achieving remarkable results for minimizing the limitation of probe pins.
Particularly when an interlocking mechanism interlocks a connecting mechanism with a drive mechanism, there is the advantage of being able to perform the continuity testing without the worker being concerned with the connecting mechanism since the connecting mechanism is capable of automatically opening and closing.
In addition, when the connecting mechanism allows the insertion of the connector housing onto a connector receiving member by maintaining the connecting mechanism at a released state in the initial condition, there is the advantage of improving the workability because of the capability for easy insertion of the connector housing into the connector receiving member.
On the other hand, in case the interlocking mechanism contains an interlocking drive mechanism or the like, because it becomes difficult to shift the connecting mechanism to a connected state, unless the connector housing is completely inserted into the connector receiving member, the worker cannot confirm the shift of the connecting mechanism visually or by actual touch, i.e., whether or not the connector housing is completely inserted into the connector receiving member.
Furthermore, the link member allows the connecting mechanism to be shifted to a released state in case the test area is in a separated state, while when the test area is in an engaging state, as if by controlling the shift of the connecting mechanism to a released state, and when the link member is provided to the test area in a relatively shiftable manner, the connector housing can easily be detached when a safety level is assumed and stays constant, thereby providing an advantage of both safety and workability.
In addition, when providing an elastic body for biasing an inserted connector housing in the connector receiving member to a removal direction, because it becomes possible to set a force level that is sufficient to eject the connector housing, and because of the capability to eject the connector housing from the connector receiving member by the elastic body, selection of the elastic body so that the connector housing can most easily be inserted can be chosen, thereby providing the advantage of further improvement of the workability.